JP2008090189A - Apparatus and method of cutting optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for cutting an optical fiber that dispense with a step of removing coating of optical fibers and that facilitate cutting of optical fibers. <P>SOLUTION: The cutting apparatus comprises: clamps 11a, 11b that clamp the optical fiber 30 including glass 31 and coating 32, on both sides of a planned cutting part CT; a circular blade member 12 that notches the coating 32 by moving orthogonally to the axial line of the optical fiber 30 at the planned cutting part CT and that also applies a score on the glass 31; and a pillow 20 that pressurizes the planned cutting part CT from the opposite side of the blade member 12 with a prescribed pressure during the notching of the coating 32 and the scoring of the glass 31. The tip end of the pillow 20 is curved along the moving direction of the blade member 12, wherein the radius of curvature r is not more than the radius R of the blade member 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical fiber cutting device and an optical fiber cutting method for cutting a coated optical fiber.

  Conventionally, an optical fiber cutting device and a cutting method as shown in FIG. 12 are known (see, for example, Patent Document 1). In this optical fiber cutting device 100, a blade 101 is provided, and a pair of upper and lower clamps 104a and 104b for holding the bare fiber 103 of the tape core wire 102 are provided on both sides of the blade 101, respectively. Further, on the side opposite to the blade 101, a pillow portion 105 is disposed so as to be movable in the vertical direction with the bare fiber 103 interposed therebetween.

  In order to cut an optical fiber using this optical fiber cutting device, as shown in FIG. 12 (A), after holding the bare fiber 103 with each clamp 104a, 104b, 104a, 104b, the blade 101 is bare. The blade 101 is moved in a direction perpendicular to the longitudinal direction of the fiber 103 (a direction from the front side to the back side of the drawing) to scratch the surface of the bare fiber 103. Then, as shown in FIG. 12 (B), the pillow portion 105 is moved downward as viewed in the figure, an external force is applied to the bare fiber 103 so that the wound is on the outside, and the bare fiber 103 is cut by cleavage. Yes.

JP-A-11-264909 (FIGS. 4 and 6)

  By the way, in the optical fiber cutting device and the cutting method described in Patent Document 1 described above, when the optical fiber is cut, the coating is removed with a dedicated remover, and then the glass is cut with a dedicated cutter. Is common. Since the core of the optical fiber is as small as φ10 μm in the single mode and φ50 to 62.5 μm in the multimode, positioning accuracy on the order of micrometers is required to reduce the connection loss. However, in a state with a cover, it is difficult to ensure positional accuracy due to deformation and uneven thickness of the cover. Further, since the state of the cut end face also affects the connection loss, it is required to use a special tool to provide a mirror surface, which is troublesome.

  In recent years, optical fibers have been cut without removing the coating because of the demand for simplified optical connection. When cutting an optical fiber using an existing cutter, it is necessary to first cut the coating and then damage the glass surface. However, in order to cut the coating in the state shown in FIG. 12A, the optical fiber is moved to the opposite side of the blade 101 only by grasping the two sides of the optical fiber with the two clamps 104a, 104b, 104a, 104b. The drag is not enough to escape and the glass surface cannot be scratched. Further, in order to make the cleaved surface of the glass a mirror surface, it is necessary to apply an appropriate tension to the optical fiber, and it is impossible to increase the drag force by increasing the clamping force.

  An object of the present invention is to provide an optical fiber cutting method and a cutting apparatus that can easily cut an optical fiber without requiring an optical fiber coating removal step.

  An optical fiber cutting device according to the present invention capable of solving the above-described problems is provided with a clamp for gripping an optical fiber including glass and a coating on both sides of a planned cutting location, and an axis of the optical fiber at the planned cutting location. The disk-shaped blade member that cuts the coating by moving in a direction orthogonal to the glass, and further scratches the glass, and the cutting position of the blade member when the coating is cut and the glass is scratched. An optical fiber cutting device having a pillow that is pressed at a predetermined pressure from the opposite side, wherein the end of the pillow is curved along the moving direction of the blade member, and the radius of curvature of the pillow is It is less than the radius.

  Further, in the optical fiber cutting device according to the present invention, the tip of the pillow is formed of a soft member, and the optical member is lifted when the optical fiber is lifted by the blade member when the optical fiber is cut. It is preferable to have a load application mechanism that presses against a planned cutting position of the fiber.

  Further, in the optical fiber cutting device according to the present invention, the load applying mechanism has a spring, and the spring constant of the spring is 0.1 N / mm or more and 0.8 N / mm or less, The acting load is preferably 50 gf or more and 300 gf or less.

  In the optical fiber cutting device according to the present invention, it is preferable that the soft member has a hardness (Hs) of 10 degrees or more and 80 degrees or less and a thickness in a pressing direction of 0.1 mm or more and 1.0 mm or less. The hardness (Hs) here is a standard hardness according to JIS K 6301 A type.

  An optical fiber cutting method according to the present invention that can solve the above-described problem is to grip an optical fiber including glass and a coating on both sides of a planned cutting location, and to the axis of the optical fiber at the planned cutting location. It is a cutting method of an optical fiber that cuts the coating by moving a disk-shaped blade member in a direction orthogonal to each other, and further gives a scratch to the glass, and then cuts by applying an external force to the planned cutting location, When the blade member is moved to cut the coating and scratch the glass, a pillow whose tip is curved with a radius of curvature equal to or less than the radius of the blade member along the moving direction of the blade member, The optical fiber is pressed against the planned cutting portion from the opposite side of the blade member.

  Further, in the method for cutting an optical fiber according to the present invention, after the glass is scratched, the optical fiber is bent by pressing the pillow against the planned cutting site, thereby applying tension to the planned cutting site and cutting. It is preferable to do.

  According to the optical fiber cutting device and the cutting method of the present invention, when cutting an optical fiber, it is possible to cut the coating with a blade member and further scratch the glass, thereby eliminating the step of removing the optical fiber coating, A simple cutting operation can be performed. Further, since the glass of the optical fiber is not exposed, handling of the optical fiber after cutting becomes easy. Moreover, since the glass of the optical fiber of cutting waste is not exposed, handling becomes easy. Furthermore, when the optical fiber glass is scratched by the blade member, the optical fiber is pressed from the opposite side of the blade member by a pillow having a radius of curvature equal to or less than the radius of the disk-shaped blade member. Load can be added. In particular, even when a multi-core optical fiber is cut, a uniform load can be applied to each optical fiber from the blade member. For this reason, the same degree of initial damage can be given to each optical fiber.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing an example of an embodiment of an optical fiber cutting device according to the present invention, and FIG. 2 is a cross-sectional view of an optical fiber showing notches provided in a coating by a blade member at a planned cutting position and scratches given to glass. 3 (A) is a front view of the leading end of the pillow, FIG. 3 (B) is a side view seen from the direction of arrow B in FIG. 3 (A), and FIGS. 4 (A) and 4 (B) are related to the present invention. FIG. 5A and FIG. 5B are explanatory diagrams showing a comparison object with respect to the present invention, and FIG. 6 is a pillow. FIG. 7 is a graph showing the relationship between the pushing amount of the pillow and the load acting on the optical fiber, and FIG. 8 is the pushing amount of the pillow when silicon rubber or NBR rubber is used as the soft member. Is a graph showing the relationship between the load and the load acting on the optical fiber, FIG. Illustration of definitive pillow load, FIG. 10 is a graph showing the relationship between the angle of the cut surface of the pillow load and glass, FIG. 11 (A) ~ (D) is an explanatory view showing a cutting step.

  As shown in FIG. 1, the optical fiber cutting device 10 of the present embodiment includes an optical fiber including a glass 31 (see FIG. 2) that is a glass fiber having a core and a cladding, and a coating 32 that covers the outer periphery of the glass 31. 30 is moved in a direction orthogonal to the axis of the optical fiber 30 at the planned cutting location CT, and the coating 32 is cut, and the glass 31 is further scratched 31a. A disc-shaped blade member 12 for applying the cutting force, and a pillow 20 that presses the planned cutting point CT from the opposite side of the blade member 12 at a predetermined pressure when the cut 32a of the coating 32 and the scratch 31a of the glass 31 are applied. Yes. The width direction curvature radius r of the tip 21 of the pillow 20 is equal to or less than the radius R of the blade member 12.

  The cutting device 10 includes a main body 13 having a substantially U-shape when viewed in cross section, and a direction perpendicular to the axis of the optical fiber 30 with respect to the main body 13 on the inner side of the U-shape of the main body 13 (direction orthogonal to the drawing). The slider 14 is slidable. The slider 14 may be manually slidable by an operator's operation, or may be slid automatically by an elastic member such as a spring or a motor. As shown in FIG. 2, the optical fiber 30 has a glass 31 at the center, and the outside of the glass 31 is covered with a coating 32. Note that the optical fiber 30 may be a single fiber or a multi-fiber.

  A blade member 12 having a disk shape with a radius R is attached to the slider 14 via a fastening member 14a. The blade member 12 can be adjusted up and down by loosening the fastening member 14a. The blade edge 12a, which is the outer peripheral edge of the blade member 12, has an acute shape, and the sharp blade edge 12a makes a cut 32a in the coating 32 of the optical fiber 30 as shown in FIG. Or scratches 31a. The blade edge 12a may not have an acute angle, that is, may become difficult to cut by repeating the work of applying the cut 32a of the coating 32 and the scratch 31a on the surface of the glass 31. In such a case, the sharp blade edge 12a can be applied to the coating 32 of the optical fiber 30 or the glass 31 by loosening or releasing the fastening member 14a and rotating the blade member 12.

  Lower clamps 11a and 11a for holding the optical fiber 30 are provided on both sides of the main body 13 with the blade member 12 interposed therebetween, and lower rubbers 15a and 15a are attached to the upper ends of the lower clamp 11a. Upper clamps 11b and 11b are provided to face the upper side of the lower clamps 11a and 11a, and the upper clamps 11b and 11b are connected at the upper part to form a gate shape. The upper clamps 11b and 11b are mounted with upper rubbers 15b and 15b at their lower ends, and are movable in the vertical direction in FIG. When gripping the optical fiber 30, the upper clamps 11b, 11b are moved upward, and after placing the optical fiber 30 on the lower clamps 11a, 11a, the upper clamps 11b, 11b are moved downward to move the upper and lower rubbers 15a, The optical fiber 30 is pinched and held at 15b. The upper and lower rubbers 15a and 15b can securely hold the optical fiber 30 and prevent inadvertent deformation of the optical fiber 30.

  A guide portion 17 is provided between the front and rear upper clamps 11b and 11b in the vertical direction. A lateral pressure is applied to the guide portion 17 and an external force is applied to the glass 31 when the glass 31 is cleaved. The pillow 20 to be moved is arranged to be movable in the vertical direction. The pillow 20 is provided at a scheduled cutting position CT (see FIG. 2). That is, the pillow 20 faces the blade member 12 with the optical fiber 30 interposed therebetween. As shown in FIGS. 3A and 3B, the pillow 20 is, for example, a columnar member having a rectangular cross section, and the tip 21 of the pillow 20 has a radius of curvature r equal to or less than the radius R of the blade member 12 as described above. Therefore, the blade member 12 is curved along the sliding direction of the blade member 12, and has a rounded shape.

  4A and 4B show a state in which a cut 32a is provided in the coating 32 of the multi-fiber optical fiber 30 and a scratch 31a is given to the glass 31 using the pillow 20 having a rounded tip. It is shown. 5A and 5B show a state in which a wound 31a or the like is imparted using a pillow having a flat tip as a comparison object with respect to the present embodiment.

  As shown in FIGS. 5A and 5B, when the tip 21 of the pillow 20 is flat, the push-up amount of the optical fiber 30 is L1 at both the end and the center, and one optical fiber 30 is pressed. The pressing force increases at the end. On the other hand, in the center that contacts many optical fibers 30 at a time, the pressing force acting on each optical fiber 30 is dispersed and lowered, and the pressing force acting on each optical fiber 30 is different. The size of the initial scratch 31a applied to 30 is different.

  Therefore, in the optical fiber cutting device 10 according to the present invention, when the multi-fiber optical fiber 30 is cut, the tip 21 is pressed by the pillow 20 rounded with the curvature radius r. Therefore, since the end optical fiber 30 is pressed by the end of the pillow 20, the optical fiber 30 is raised by L1 by sliding the blade member 12 (moving in the arrow direction in the figure). On the other hand, since the center optical fiber 30 is pressed at the center of the pillow 20, it is pushed up by L2 (> L1) as the blade member 12 slides. That is, since the pressing force is increased at the center where the pressing force is distributed to the plurality of optical fibers 30, the pressing force acting on each optical fiber 30 from the blade member 12 acts uniformly, and the same is applied to each optical fiber 30. It is possible to apply an initial scratch 31a of a degree.

  For example, when cutting the 12 optical fibers 30 having a radius R of the blade member 12 and a radius r of the tip 21 of the pillow 20 of 20 mm and a pitch of 250 μm, the optical fibers at both ends and the center optical fiber The difference in pushing amount (L2−L1) is about 90 μm.

  Next, a load application method that is less dependent on the push-in amount will be described. The pillow 20 is required to have a hold function for fixing the optical fiber to some extent and a load application function necessary for introducing an initial flaw. In order to satisfy the hold function, as shown in FIG. 6, the tip 21 of the pillow 20 may be formed of a soft member 22 (spring constant k1). Here, as the soft member 22, for example, a rubber material or a sponge material can be used. The hardness (Hs) defined by JIS K 6301 A type is 10 degrees or more and 80 degrees or less, and the thickness in the pressing direction is 0.1. 1 mm or more and 1.0 mm or less. In this case, how the load is applied to the optical fiber 30 at the time of cutting the blade changes abruptly with respect to the indentation displacement (= material deformation) as shown in the range of FIG. This means that although depending on the spring constant of the material, the load varies greatly depending on the amount of pushing.

  Therefore, in order to reduce the difference in the applied load even when the pushing amount is different, a spring 23 (spring constant k2) is provided as a load applying mechanism as shown in FIG. Here, the spring 23 has a smaller spring constant than the soft member 22 (that is, k1> k2), and the spring constant k2 is set to a predetermined load (a load appropriate for applying the initial scratch 31a) in advance. . It is desirable that the spring constant k2 is 0.1 N / mm or more and 0.8 N / mm or less, and the load acting on the pillow 20 is 50 gf or more and 300 gf or less. In the example of this embodiment, the spring constant k2 is 0.15 N / mm.

  Accordingly, in FIG. 7, when the load due to the deformation of the soft member 22 at the tip 21 of the pillow 20 is balanced with the set load of the spring 23 (point (C) in FIG. 7), the load shifts to the load by the spring 23. . Since the spring constant k2 of the spring 23 is small, the change in the applied load can be kept small even after the point (C) even if the pushing displacement is slightly different.

  FIG. 8 shows the relationship between the push-in amount (δB) and the load (gf) when silicon rubber or NBR rubber is used as the soft member 22 and a coil spring is used as the spring 23. The used silicon rubber has a hardness (Hs) of 50 degrees and a thickness in the indentation direction of 0.5 mm. The NBR rubber used has a hardness (Hs) of 60 degrees and a thickness in the indentation direction of 0.5 mm. In the case of silicon rubber, δB = 0.3 mm, and in the case of NBR rubber, δB = 0.1 mm corresponds to the point (C) in FIG. 7, and a predetermined spring load is applied beyond this.

  From the viewpoint of connection characteristics, it is desirable that the cut surface of the glass 31 of the optical fiber 30 has a small angle with respect to the plane perpendicular to the optical axis and has no cross-sectional defects. For this reason, it is required to apply an appropriate initial scratch 31a and to apply appropriate tension and bending stress thereafter. Here, since the size of the initial scratch 31a is determined by the load of the pillow 20, it is important how the blade member 12 is scratched in a state where an appropriate load is applied. As shown in FIG. 9, in the optical fiber cutting device 10 according to the present invention, the load of the pillow 20 is the sum of the load fa due to the deformation of the soft member 22 and the load fb due to the spring 23. Note that it is easier to adjust the load fb by the spring 23 than to adjust the load fa by the soft member 22.

  FIG. 10 is a graph showing the result of measuring the end face angle of each of the optical fibers 30 with a single coating 32 (coating / glass = 125 μm / 80 μm) by changing the set load of the pillow 20. The blade member 12 is a round blade having a diameter (2R) of 20 mm and an angle of the tip 21 of 60 ° made of super steel. An acute angle (30 °) is preferred in order to make the cutting surface of the coating cleanly cut (small deformation) in the range of 30 ° to 90 °. As a result, in the case of cutting the single-core coated optical fiber 30, it is understood that the optimum load is about 50 to 70 gf, particularly 60 gf. Although cutting is possible even at about 40 gf, since the initial scratch 31a is too small, cross-sectional defects such as hackles may occur. On the other hand, at 100 gf, the initial scratch 31a is too large to control the cut angle. Moreover, since glass may be broken at the time of blade introduction, it is inappropriate.

Next, an optical fiber cutting method using the above-described optical fiber cutting device 10 will be described.
11A to 11D show an example of an embodiment of an optical fiber cutting method according to the present invention. First, the holder 16 fixing the optical fiber 30 is fixed to a recess 13a provided in the main body 13 of the cutting device 10 (see FIG. 1), and as shown in FIG. 11A, the upper and lower clamps 11a, The optical fiber 30 is held between 11b. As shown in FIG. 11 (B), the pillow 20 is urged downward by its own weight and the spring 23, and the distal end portion 21 of the pillow 20 is pressed against the optical fiber 30 to exert a side pressure. The pillow load at this time is set to be optimum as described above.

  In this state, the slider 14 is moved from the front side to the back side of the drawing, the cutting edge 12a of the blade member 12 is brought into contact with the optical fiber 30, and the coating 32 of the optical fiber 30 is cut while the side pressure action of the pillow 20 is applied. . Further, when the blade member 12 moves, as described above with reference to FIG. 2, the coating 32 is completely cut and comes into contact with the glass 31 of the optical fiber 30 to give an initial flaw 31 a. Thereafter, the pillow 20 is once lifted against the urging force of the spring 23. When the blade member 12 passes through the optical fiber 30 as shown in FIG. 11C, the pillow 20 falls downward by the action of the spring 23 as shown in FIG. The glass fiber 31 is cleaved from the initial scratch 31a and is broken by causing the optical fiber 30 to bend and applying a tension accompanying the bending.

According to the optical fiber cutting device and the optical fiber cutting method described above, since the coating 32 can be cut by the blade member 12 and further the glass 31 can be scratched, in the state of the optical fiber 30 provided with the coating 32. Cutting work can be performed. Moreover, since the glass 31 of the optical fiber 30 is not exposed when cutting, the handling of the optical fiber 30 after cutting becomes easy. Also, the optical fiber that becomes cutting waste does not expose the glass, and handling such as post-processing becomes easy.
Furthermore, since the tip of the pillow 20 that holds the optical fiber 30 at the time of cutting by the blade member 12 is curved with a radius of curvature r equal to or less than the radius R of the disk-shaped blade member 12, the multi-fiber optical fiber 30 is cut. In doing so, a uniform load can be applied from the blade member 12 to each optical fiber 30. Therefore, the same degree of initial scratch 31a can be given to each optical fiber 30, and each optical fiber 30 can be cut uniformly.

It is a block diagram which shows embodiment which concerns on the cutting device of the optical fiber of this invention. It is sectional drawing of the optical fiber which shows the notch | incision provided in the coating | cover by the member at the cutting position, and the damage | wound provided to glass. (A) is the front view of the front-end | tip part of a pillow, (B) is the side view seen from the arrow B direction in FIG. 3 (A). (A) And (B) is explanatory drawing which shows the state which gives a cut and a damage | wound to a multi-core optical fiber using the optical fiber cutting device concerning this invention. (A) And (B) is explanatory drawing which shows the comparison object with respect to this invention. It is a block diagram which shows the load provision mechanism of a pillow. It is a graph which shows the relationship between the pushing amount of a pillow, and the load which acts on an optical fiber. It is a graph which shows the relationship between the pushing amount of the pillow when silicon rubber or NBR rubber is used for a soft member, and the load which acts on an optical fiber. It is explanatory drawing of the pillow load at the time of a cutting | disconnection. It is a graph which shows the relationship between a pillow load and the angle of the cut surface of glass. (A)-(D) are explanatory drawings which show a cutting process. It is explanatory drawing which shows the conventional optical fiber cutting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cutting device 11a, 11b Clamp 12 Blade member 20 Pillow 21 Tip 22 Soft member 23 Spring (load provision mechanism)
30 Optical fiber 31 Glass 31a Scratch 32 Coating 32a Incision CT Cut planned location R Radius of blade member r Radius of pillow tip

Claims (6)

A clamp for gripping an optical fiber including glass and a coating on both sides of a planned cutting position, and moving the coating in a direction orthogonal to the axis of the optical fiber at the planned cutting position, and further cutting the coating. An optical fiber cutting device comprising: a disc-shaped blade member for imparting a pressure; and a pillow that presses the planned cutting portion from the opposite side of the blade member at a predetermined pressure when the coating is cut and the glass is scratched. There,
An optical fiber cutting device, wherein a tip of the pillow is curved along a moving direction of the blade member, and a radius of curvature is equal to or less than a radius of the blade member. The optical fiber cutting device according to claim 1,
The front end of the pillow is formed of a soft member, and has a load applying mechanism that presses the soft member against a planned cutting position of the optical fiber when the optical fiber is lifted by the blade member when the optical fiber is cut. An optical fiber cutting device. An optical fiber cutting device according to claim 1 or 2,
The load applying mechanism has a spring, the spring constant of the spring is 0.1 N / mm or more and 0.8 N / mm or less, and the load acting on the pillow is 50 gf or more and 300 gf or less. An optical fiber cutting device. An optical fiber cutting device according to claim 2 or 3,
The soft member has a hardness (Hs) of 10 to 80 degrees and a thickness in the pressing direction of 0.1 to 1.0 mm. Grip the optical fiber including glass and coating on both sides of the planned cutting location, move the disk-shaped blade member in a direction perpendicular to the axis of the optical fiber at the planned cutting location, cut the coating, Furthermore, after giving a scratch to the glass, an optical fiber cutting method for cutting by applying an external force to the planned cutting location,
When the blade member is moved to cut the coating and scratch the glass, a pillow whose tip is curved with a radius of curvature equal to or less than the radius of the blade member along the moving direction of the blade member, A method of cutting an optical fiber, wherein the optical fiber is pressed against the planned cutting portion of the optical fiber from the opposite side of the blade member. An optical fiber cutting method according to claim 5, comprising:
A method of cutting an optical fiber, wherein after the glass is scratched, the optical fiber is bent by pressing the pillow against the planned cutting position, thereby applying tension to the planned cutting position.

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